Non-Labor Input Quality and Small Farms in Sub-Saharan Africa : A Review

Adoption of non-labor agricultural inputs, including pesticides and mineral fertilizers,remains low among small-scale farmers in many low-income countries. Accurate measurement of the quality of theseinputs and of quantities deployed is essential for assessing economic returns, understanding the drivers of agriculturalproductivity, and proposing and evaluating policies for increasing agricultural production. Reviewing evidenceregarding the quality of mineral fertilizers and pesticides available to small farmers in Sub-Saharan Africa, this papersummarizes four key findings. First, the available evidence on non-labor input quality to date centers mostly on ureafertilizer and glyphosate herbicide, with limited assessment of other important inputs, including multi-nutrientfertilizers. Second, the evidence shows that nitrogen shortages are exceedingly rare for urea, although qualityproblems are more common in fertilizer blends including nitrogen, phosphorous, and potassium blends, as well asdiammonium phosphate, and in glyphosate herbicide. Third, although nutrient shortages in nitrogen, phosphorous, andpotassium fertilizer blends and diammonium phosphate fertilizer blends are likely attributable to problems withmanufacturing and storage, problems with available herbicides could be due to manufacturing issues,counterfeiting, or adulteration. Fourth, although farmers are broadly suspicious of the quality of mineral fertilizerand pesticides, evidence from several studies suggests that these beliefs do not reflect lab-based assessments ofquality. In light of these findings, this paper recommends best practices for evaluation of non-labor input quality andsummarizes research evaluating farmer assessment of fertilizer and pesticide quality. The paper concludes byidentifying key evidentiary gaps related to measuring non-labor agricultural input quality and use, and recommendsspecific topics for future research.